Leonard J. Schulman. The Quantifier Semigroup for Bipartite Graphs. Electr. J. Comb., 18(1), 2011. [doi]
@article{Schulman11-0, title = {The Quantifier Semigroup for Bipartite Graphs}, author = {Leonard J. Schulman}, year = {2011}, url = {http://www.combinatorics.org/Volume_18/Abstracts/v18i1p123.html}, researchr = {https://researchr.org/publication/Schulman11-0}, cites = {0}, citedby = {0}, journal = {Electr. J. Comb.}, volume = {18}, number = {1}, }